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Some curious valve differences

Okay, gang, time for some valve schooling for yours truly.

Can someone explain to me the reason for the following differences in the following valves:

1. Mistaken question, withdrawn.
2. Mistaken question, withdrawn.
3. If, as Tuna says, the reg spring packs in the classic valves never wear out, why did AGD elect to go with a dual counter-wound spring system in the RT-style valves? Answered!
4. Related to #3, do these dual counter-wound springs ever wear out? Answered!
5. Why do the RT (classic) and ReTro (and some E-Mag?) valves have only the single o-ring hole milled in the on/off well rather than being completely bored out like the earlier Classic and later X-valves? Also, is it in fact true that some E-mag valves have only the single o-ring hole? Answered!
6. Why is the reg/valve body threading on all RT-type valves different from that of the classic valves? Answered!
7. Is the back cap of the RT-style valves stainless? If so, what prevents it from wearing the ano on the reg body during adjustment? Answered!
8. Did later versions of the ReTro valve move to the double o-ring well after the fashion of the later E-mag valves?
9. Did all, some, or none of the RT Pro valves have the double o-ring well?

No more cigars for you. Too many questions that i don't have answers for.

It probably was the influence of the good cigar and the better company, not to mention the fine mags. It's their fault, not mine. Whatever the cause, I figured either somebody could help me, or Nobody could help me.

Originally Posted by Dayspring

I can answer some of number 5-

Yes - some emag valves did in fact only have the 1 o-ring instead of the 2. There was a certain valve # that it started changing at, but I don't remember it.

I don't have anymore E Mag valves , but didn't realize there was any length difference on the reg? I will say that I measured my Retro Valve and the reg is the same size as the X valve.

It is entirely possible that all of them are the same length. I've never actually had them in my hands side by side. The first and second questions are based only on multiple photos I've seen with both retro and e-mag valves side by side, and the regs definitely appear to be a bit shorter on the e-mag valves. That could of course be an optical illusion, and if so, it would be good to lay it to rest and be done with it, since the size discrepancy (if it exists) really makes no sense.

It is entirely possible that all of them are the same length. I've never actually had them in my hands side by side. The first and second questions are based only on multiple photos I've seen with both retro and e-mag valves side by side, and the regs definitely appear to be a bit shorter on the e-mag valves. That could of course be an optical illusion, and if so, it would be good to lay it to rest and be done with it, since the size discrepancy (if it exists) really makes no sense.

I have had both and really don't remember there being a size difference at all.

As for #5, I believe this had to do with the introduction of the ULT didn't it?

My GUESS for # 6 was going to have to do with the differences in strength between aluminum and SS making the aluminum valves needing to be thicker walled for safety, but then I remembered the original RT style valves had SS front sections so that blew that out of the water.

E-mag reg is clearly shorter, or seems to be. The difference is even more pronounced when directly side by side in other pics I've seen.

As for #5, I believe this had to do with the introduction of the ULT didn't it?

No, this started with the classic RT back in '96, well before any ULE/ULT stuff came into being.

My GUESS for # 6 was going to have to do with the differences in strength between aluminum and SS making the aluminum valves needing to be thicker walled for safety, but then I remembered the original RT style valves had SS front sections so that blew that out of the water.

I was thinking maybe owing to higher internal pressures, or maybe the tendency of classic valves to unscrew under pressure, but that is simply a guess.

I just took calipers to both of your pictures and the regs in both are the same length.

Just did the same, and looks like you may be quite correct. There is a slight variance, but probably owing only to picture distortion. Seems I mistakenly conflated the E-mag valve with the Classic RT valve, which is the same length as the classic valve, both of which are shorter than the X valve. Made sense that the newer RT-type valves would be dimensioned differently than the classic RT valve, but made no sense that they would then be different from one another. Good. That seems settled.

And I meant when they changed to the X Valve, they began doing the double O-ring which is used in a ULT. ULT isn't used in the Classic Valve.

Understood. But given that some of the stainless E-mag bodies had the double o-ring well, presumably before the advent of the X valve, then maybe there were other motivations besides the use of the ULT kit.

Understood. But given that some of the stainless E-mag bodies had the double o-ring well, presumably before the advent of the X valve, then maybe there were other motivations besides the use of the ULT kit.

I'm not sure about that. I know some of the early Emag valves used the Urethane O-rings, but were they single or double? My Retro valve has a single o-ring in it, not the quad o-ring found in Emag valves.

If I understand correctly, E-mag valves went to the buna quad ring owing to the need for reduced friction on the on/off pin to aid in reset. The only exploded views I've seen are the dual ring setups with quad ring nestled inside poly. The other systems had no such need, hence the poly rings were used since they are vastly more durable than buna.

Machining-wise, you would only bother with the shouldered pocket in order to get rid of one of the o-rings. That didn't prove particularly useful and a quad o-ring should be tight in that pocket since it sits inside the larger o-ring with the edges hanging over (defeating the low friction need of the emag). I always thought of the shoulder as another vestigial feature of the classic RT that just didn't add as much value as the difficulties it caused. It just didn't suffer immediate demise like the banjo bolt and hard line.

Just did the same, and looks like you may be quite correct. There is a slight variance, but probably owing only to picture distortion. Seems I mistakenly conflated the E-mag valve with the Classic RT valve, which is the same length as the classic valve...

since i have all three in possession, i'd just like to mention the rt classic, rt pro and emag reg bodies are all the same length. makes sense, as they're all basically identical internally.

My reverse minimag valve I had was the same length as my classic RT valve. And I know for a fact a classicRT and RTPro valve are identical other than OD considering I own both. Along with that. A RTPro back half and classicRT back half can be interchanged and work perfectly..... Well other than the rtpro back being to large to fit in a classic rt.

My reverse minimag valve I had was the same length as my classic RT valve. And I know for a fact a classicRT and RTPro valve are identical other than OD considering I own both. Along with that. A RTPro back half and classicRT back half can be interchanged and work perfectly..... Well other than the rtpro back being to large to fit in a classic rt.

Interesting . . . The plot thickens! I wonder if anyone has all, and can simply lay them out side by side for direct , end-of-discussion comparison.

valve fronts. from left to right: emag, rt classic, rt pro and minimag. they are all exactly the same length. the emag is only longer due to the lvl 10 powertube tip.

valve regulator backs. the emag, rt classic and rt pro are the same length at 1.492". the minimag is 1.315". the measurements were taken with digital calipers.

there is no reason to suggest the x-valve is any different from the other rt valves regarding dimensions. they have the same internals, so they must have the same inner dimensions, and should have the same outer dimensions. the other rt valves all have aluminum reg backs as well, and are compatible (barring the rt classic) with each other as far as fitment into bodies, etc is concerned.

Can someone explain to me the reason for the following differences in the following valves:

1. Mistaken question, withdrawn.
2. Mistaken question, withdrawn.
3. If, as Tuna says, the reg spring packs in the classic valves never wear out, why did AGD elect to go with a dual counter-wound spring system in the RT-style valves?
4. Related to #3, do these dual counter-wound springs ever wear out?
5. Why do the RT (classic) and ReTro (and some E-Mag?) valves have only the single o-ring hole milled in the on/off well rather than being completely bored out like the earlier Classic and later X-valves? Also, is it in fact true that some E-mag valves have only the single o-ring hole?
6. Why is the reg/valve body threading on all RT-type valves different from that of the classic valves?
7. Is the back cap of the RT-style valves stainless? If so, what prevents it from wearing the ano on the reg body during adjustment?
8. Reserved.
9. Reserved.

Thanks very kindly!

3) Two springs in parallel have a lower oscillation period than a single spring with the same spring constant. That allows the regulator to be more precise and faster to react to any changes in pressure.

4) All springs wear out if the number of oscillations above a given stress level are exceeded. Most springs should handle millions of cycles within their parameters if the fatigue levels are not exceeded. that is much more than the life of a mag valve, especially since these springs don't move much.

5) The early RT, retro, emag valves had the single on-off hole to cut down on the parts needed. It eliminated one oring. Later emag and retro valves and all X-valves went back to having two orings. I suspect it was because the machining process was much easier.

6) The threading on the retro valve bodies is different from the classic bodies so that you can't install one on the other by mistake.

7) Yes, the back cap is stainless. Good cuts of lots of very fine threading allows a good mate between the threads. The number of threads in contact with each other is a high number which reduces the amount of force on any one point. The spread of the force over a large area keeps the force threshold below the value that the oxide layer breaks down which prevents it from wearing out.

Except for the Automag in front, its usually the man behind the equipment that counts.

athomas, just to clarify, are you saying that some of the later ReTro valves went to the double o-ring well just as with the E-mag, or are you lumping the RT Pro valves in with the ReTro valves for simplicity?

Did all, some, or none of the RT Pro valves have the double o-ring well?

I did link the retro and RT pro valves together, since they are essentially the same valve. All of the early "retro style" reactive trigger valves had the single oring well. All later versions had the double oring well. All RT valves and RT Pro valves were early valves, so they all had the single oring well. Only the retro and emag valves came in both flavours as far as I know. If you see any RT Pro valves with a double oring well, it was probably machined that way after the fact so that it could have an ULT installed.

I'm now asking for specifics simply for the purpose of going into the market to get one of these older stainless bodied valves, but just want to be sure of having the double o-ring well, preferably factory machined.